I suspect:
Because Brave Browser (MacOS) has a problem downloading large files - completely:
‘Downloads Frequently Fail While Adding to Dock Number - #2 by 289wk’
A while back in this summertime, I had installed for test purposes, (a problematic) Brave Browser Beta:
‘Unable to download files or upload files in brave browser - #15 by 289wk’
. . . and because that did not work, I had promptly un-installed all of that BB Beta installation.
I suspect, that somehow, Little Snitch stumbled upon a trace of that former BB Beta installation - despite my having deleted/removed all of that BB Beta installation.